Posted
by
kdawson
on Friday May 21, 2010 @11:39AM
from the no-safety-in-numbers dept.

scribblej writes "Many large companies use Microsoft's Dynamics GP product for accounting, and many of these companies use it to store credit card numbers for billing customers. Turns out these numbers (and anything else in GP) are encrypted only by means of a simple substitution cipher. This includes the master system password, which can be easily selected and decrypted from the GP database by any user. Quoting: '[Y]ou DON'T HAVE TO GIVE ACCESS TO THE DYNAMICS DATABASE. What that means is if you create a base user in GP, that user can log into the SQL server and run a select statement on the table containing the "encrypted" GP System password. Not good.'"Update: 05/22 02:57 GMT by T: The original linked post has been revised in a few places; significantly, the following has been added as a correction: "By default, GP gives the user access to the DYNAMICS database but the user CANNOT login to the SQL server using SQL Enterprise Manager."

And storing credit card details in this way is in direct violation of the PCI-DSS which as a merchant the companies will have attested that they are in compliance with. If they get caught or worse leak data then there are severe financial penalties.

Actually, that's not the case - I don't believe that PCI mandates "good" encryption, just encryption. Besides, one thing that it absolutely does mandate, at least for service providers (the portion of PCI I'm most familiar with), is that your database be in a different, firewalled, network segment than your application server. So even if GP is creating accounts on the DB server, nobody other than the application should be able to just connect to it anyway. Of course, having just gone through our audit, I

What, do you live in a windmill powered cabin in the woods? Unless you live completely off the grid (impossible, in your case, as you post to slashdot) nearly every company you do trade with uses Microsoft products.

Value itself is an illusion, other than what value we give something. Beauty is in the eye of the beholder.

So if most of the world agrees that these numbers have value, they do, whether or not the assets are physical. Oh yes, things can be real without being physical -- or how would you feel if everything you ever created inside a computer was wiped out in a hard disk crash?

Unless you're going to claim that all currency is an illusion, you're again going to have to provide a lo

Um, yeah, that is a substitution cipher because each byte is encoded by substituting a different specific byte. It's just a substitution that's really easy to do on a computer with a simple mathematical operation.

Whoever coded the "encryption" routine really dropped the ball. SQL Server supports AES encryption on individual fields. The first result of a Google search for "sql server field encryption" points to an MSDN article with code examples of how to use AES-256 encryption.

How do these things keep happening? There have to be mistakes on so many levels. Whoever developed the spec obviously was clueless. The person who coded the spec was probably clueless, and/or didn't have the authority to do things the right way. The tools to make these applications secure are available. You'd think that a Microsoft coder using a Microsoft database could use the Microsoft solution properly.

The more I deal with corporate America and the people who find themselves in charge of projects, the more I believe that competence really is a Bell curve with the center of the curve being INCOMPETENT, the far left is DISABLED. How do these people sleep at night? The only thing that I can figure is that they really are ignorant. If I do something half assed, it bugs me. It keeps me up at night. So either these people just don't give a rats ass and are working in a culture that lacks accountability, or they are completely ignorant and are working in a culture that lacks accountability. A friend of mine once told me, "Most people don't do the right thing because it is the right thing. They do the right thing because they fear the consequences of getting caught doing the wrong thing." Every where I look in society, there are fewer and fewer consequences.

I have the displeasure of working with Great Plains regularly, and this isn't surprising at all.

A couple of points for the panic stricken:

1. Great Plains uses SQL logins and it hashes the passwords of users created from within GP. Since 9.0, it salts this hash using the sql server name. A GP user other than sa can NOT login to SQL Enterprise Manager with their GP credentials. That encryption has NOT been broken (yet). (That WOULD be a real problem.)

2. The ability to decrypt the System password is useless if you can't query the system password from the database. If your users have the ability to query any table in the database directly, then you have a bigger problem than weak encryption.

3. GP overlays role and task based security on top of the SQL login mechanism. Having the decrypted System Password is less useful if your application user doesn't have the ability to reach the User Setup or Security Options menus. These menus should be turned off for everyone not in the GP PowerUser role.

Is this great for GP? No. Neither is it the harbinger of the apocalypse.

ie; "Brute." (pronounced "Brut-AY"Getting back to the main story, let me add "Doh!" That's a major back door. And Microsoft, wanting to be our gatekeepers in so many ways and even with this big security initiative they've been trying to get everyone to believe they are on, is just sort of sluffing it off with their usual sheepish "Well, its not likely to actually happen." nonsense.

There, fixed that for you. Universally accepted as what he would have said today to mean the same thing as he did then, whether by speaking the first half of a Greek curse or just by turning his eyes away from his traitorous friend.

Thats a good step, but because of the improvement of computation technology in the last few years, I am am using rot104, which is four times the strength of rot26. I am planning a move to rot208 sometime this year, but it is non-inconsequential with any real volume of data. But the fact is, you need to keep ahead of the curve to insure that the alphabet soup agencies can't read your wow chat logs...

Not that long ago, competent security was a criminal offense to export. It still is, unless the code is Open Source (and we all know how Microsoft loves Open Source). The practical difference between a Caesar cipher and DES is that the Caesar cipher is faster so more transactions can be performed. You could do more leaving things in plain-text, but regulations usually require encryption of some sort for this kind of data. However, those same regulations don't usually stipulate any particular strength of encryption, so Caesar becomes ideal. The high throughput will sell better and the absence of security means it evades export controls. You end up with the largest possible market.

If there was a recognized, official (or even semi-official) standard API and ABI for cryptography libraries, ITAR would be less of an issue. You could swap out any crypto library in any product and swap in an alternative. You could then use any crypto library (and therefore any crypto algorithm) you liked.

If standards better-mandated what level of security was required, weak algorithms would never be used. No corporation would dare risk the penalties and so no vendor would dare supply soft crypto.

The market's preference for high throughput is perfectly reasonable, but it is often unwilling to invest in security - which is why there are so many issues of this kind. If corporations were more willing to invest in securing their systems, say by using hardware crypto engines to get the high throughput they needed, they would be able to use essentially bullet-proof algorithms without harming the amount of data they could manage.

Not that long ago, competent security was a criminal offense to export. It still is, unless the code is Open Source (and we all know how Microsoft loves Open Source).

I'm sure as heck no Microsoft fan, but they've been exporting strong cryptographic components for a long time now, and not in an open source format. Please reference the following materials for further guidance on this topic:

The practical difference between a Caesar cipher and DES is that the Caesar cipher is faster so more transactions can be performed.

Umm, no?

Caesar, and substitution-based ciphers in general, are so easy to break that they're given as puzzles in the daily newspapers (some aphorism is encrypted with a substitution cipher; you need to figure out what it is). Basically, you know the frequencies with which various letters, pairs of letters, etc. appear in English text; so you can compute the frequencies with which the characters in the ciphertext appear and determine a correspondence that way.

DES is sufficiently weak that it is possible to build a home-grown cluster that can break a DES key in minutes. Yes, DES is "strong" in the sense that the algorithm itself has no significant flaws that anyone can detect, but when dealing with a credit card system where it's quite plausible that each card could have a thousand dollars available on it on average, obtaining 500 cards would cover the cost of the EFF's DES-breaking machine and therefore cover the costs. Everything else would be sheer profit for

The practical difference between a Caesar cipher and DES is that the Caesar cipher is faster so more transactions can be performed. You could do more leaving things in plain-text, but regulations usually require encryption of some sort for this kind of data. However, those same regulations don't usually stipulate any particular strength of encryption, so Caesar becomes ideal.

Actually, RC4 is not that much slower than Casear, mainly because is implemented sort of like Caesar with extra steps to modify the substitution table at runtime. OpenSSL can do RC4 on modern hardware faster than 300 MB/s. Even though it is as a "combiner" stream cipher and as such tricky to actually use securely, it would be much better than the probably ad-hoc implemented Caesar.

If there was a recognized, official (or even semi-official) standard API and ABI for cryptography libraries, ITAR would be less of an issue.

You mean like their official ones [microsoft.com]? They could have used their own crypto API, but they didn't.

If standards better-mandated what level of security was required, weak algorithms would never be used. No corporation would dare risk the penalties and so no vendor would dare supply soft crypto.

You are right - this is 50% of the problem here. The other 50% is MS just being lazy.

Well, yes. If the IT managers can't tell the difference between Caesar cipher and AES, then it is arguably lazy to use Caesar. Mind you, less work done for the same income from sales equals more profit. And in a world (and stockmarket) driven by profit margins, voluntarily cutting those margins makes no business sense. (It's why the highest-risers in the stockmarket are also the high-risks and also the ones tied to companie

Not that long ago, competent security was a criminal offense to export. It still is, unless the code is Open Source (and we all know how Microsoft loves Open Source). The practical difference between a Caesar cipher and DES is that the Caesar cipher is faster so more transactions can be performed.

Depends on your definition of "not that long ago." Since 2000, the US has lifted many restrictions on export. What MS used is a simple cipher that they've used since Roman times (hence the name Caesar). Even if

zlib is ok, but other people use szlib or other compression libraries. Huffmann encoding as a form of compression is block-based, zlib is stream-based. These are essentially also the only two types of encryption, as far as data transfer is concerned.

However, most OS' already have the concept of block devices and stream devices. In the same way that a program that operates on a streamed input and/or streamed o

Whether the folks at Microsoft wrote this themselves, or whether they instead paid $1.1 billion for this software 9 years ago it is still pretty much the same thing. Either way this makes the folks at Microsoft look like amateurs. This is precisely the sort of thing that only closed source proprietary software can get away with.

Where was the much-vaunted Security Development Lifecycle process (http://blogs.msdn.com/sdl/)? I guess the threat model consisted of a six month old baby pounding on a keyboard.
The responsible engineer(s), PMs, and VP should be fired.

Yeah, but this isn't a security flaw due to an oversight or simple mistake. This is a massive downright idiotic flaw! How the HELL did this make it into a product?

Because the claims that Microsoft has good, or even competent, programmers, engineers and managers is at best a myth. That myth has been put to rest many, many years ago, but the marketing, astroturfing [zdnet.com], and lobbying firms keep bringing it up again and again. Anyone repeating that is probably on the payroll of one of those firms or so dumb that they should be bitchslapped into next week for opening their mouth.

Seriously, these problems are synonymous with Microsoft and the passivity that allows them to

Well, that's what I mean. pserver is insecure and never pretends to be anything more than it is--a barebones security mechanism that won't thwart anyone with a genuine interest in stealing passwords. All it would do is keep someone from *accidentally* seeing somebody else's password if they were monitoring network traffic. That's about it.

That Microsoft is using basically the same thing to secure a corporate accounting system that holds genuinely sensitive data is both terrifying and laughable.

I don't know if this is any news at all. Most ERP systems do not have the data in the database encrypted at all. You should never give any direct access to your ERP database to anybody. If absolutely necessary, just create a view in another DB schema and give a read access to it only to selected users (so they could access for example the inventory information useing excel/access).

Classical ciphers, in discussions about modern computing, can't reasonably be considered on the same footing as modern ciphers. Using a classical cipher is no better than not using a cipher at all, hence no encryption.

But hey, this is slashdot where pedantry passes for insightfulness, so what the hell.

You should never give any direct access to your ERP database to anybody

That's slight overkill. I would encourage you to create proper database users, and grant them select/update/insert/delete rights only as appropriate. If you need per-column permissions, create views that hide those columns, and if they need read/write access, provide instead-of triggers on those views to support their needs.

The main reasons I would encourage you not to let users have direct access:

1) Users don't know what they're seeing, they don't know which lookup tables to join to, or they don't understand how the data's organized. They'll write their own reports, come to the wrong conclusions, convince management of their erroneous beliefs, and you'll have to clean up the mess. "I got my data from the database" shouldn't be good enough.

2) Most ERP products (really, most database-backed products) are not built to keep themselves truly logically consistent without the help of some outside application layer. There are lots of reasons for that: developers are taught that databases are just for storage, they don't want to learn procedural SQL, they're trying to be database-agnostic the only way they know how,... Giving users write access means they can easily get all the data out of synch (I don't just mean foreign keys here, thank you) by performing only half of a complex operation the application layer would have guaranteed fully done.

To be honest, it sounds like neither anonymous nor yourself have dealt with ERP systems at a database level. I'll give you a brief overview of why none of that works. First, there are six companies in my database and they do over 100 million in transactions every year. That database is 60,000 tables and there are only six users of the system. The database is only accessible from an accounting or management VLAN for obvious reasons. Going through and figuring out 10s of thousands of tables, triggers, procedu

It's true, I wasn't the DBA for Lawson (on Oracle.) But it was fun to discover how much it kept of its Cobol roots, down to the "padding" fields that you would traditionally leave in records so you could add fields later without having to rewrite the files. (They were still occasionally used that way, even inside Oracle.) I love legacy code. Fun times.

Number of tables isn't exactly an excuse in itself, though the fact that they're poorly documented might be. My current database has (truly) over a thousand d

Yes but this is GP we are talking about there really is no "Application Server" the clients all connect to the database! The users running the client therefore must have access to connect to the database and do DML queries on many objects. Any users that actually need to run the application and not some limited web front end you have built or something are SQL users. The only real workaround is to only allow database connections from selct hosts and have one of those hosts be a terminal server. The best part is the GP application has lots bugs when running under terminal services!

I figure that the variation of Caesar Cipher, ROT13, was easy to decipher so for maximum security, I always run it through the ROT13 encoder twice before I send it. Hell, I'm encoding this message in that method now so it will have to take a bit of cunning for you to read this comment. So if you've managed to read this, congratulations, you are qualified to work in Microsoft's security department.

I use the term "encryption" loosely in this article. As you read on, you'll realize why...

I've been doing some work on a plugin for Microsoft Dynamics GP, which is an accounting system aimed at Medium sized to Large businesses. To give you an idea of what type of application this is: There are companies that pay somewhere around $10,000-$15,000 to consultants or VARS (Value Added Resellers) to implement a Microsoft Dynamics GP solution for their business. Many of the VARs have their own plugins and solutions for Microsoft Dynamics GP, usually written in.NET or Dexterity. The process of installing and maintaining GP is an industry all it's own and it's not cheap for a company to maintain this accounting system.

I've been searching for the "encryption algorithm" or at least some way other way to "encrypt" data in GP in some other way than within Dexterity code. I was really hoping that there would be some.NET library that would do this for me, but I was never able to find anything that would help me do this. So, I became interested in what type of "encryption" this is. Somewhere (I can't remember where) I found something that indicated that the it's a symmetric key encryption algorithm. The message boards were not much help either. Anywhere I went, I basically saw this same type of statement, "the encryption algorithm is a closely guarded secret".

Today, while doing some testing, I noticed something with data that we were saving to a field which utilizes the GP "encryption". The plugin I was testing puts data in an encrypted field (not that it needs to because it's not sensitive in nature), and I was testing with the same values each time. As I would expect, I saw the same data stored in the field in the database for each row in the table. However, I noticed that one of the entries was different, by 2 characters. That seemed very odd to me. After looking at it some more and conducting some more tests, it looks like I simply miskeyed my test data, but it prompted me to take another look at this.

After trying a couple different combinations of test data, it became very obvious that changing only one character in the test data appeared to only alter 2 characters of the encrypted data. So I ran through a battery of tests, and came up with this:

Yep, it's basically your run-of-the-mill Substitution cipher. The worst part, there's evidence all over the place that this was a VERY weak encryption algorithm for awhile, but nobody seemed to pay any attention to it when people were asking how they could reset passwords of users in the database (Post 1 - Post 2)

I did some more searching, because there is ABSOLUTELY NO WAY THAT I AM THE ONLY ONE THAT SAW THIS... I found a good write up on the MSDN blogs that explains pretty well how the GP encryption was used (here).

The article is evidence to support a theory that I have, which is after GP moved to SQL server authentication, the encryption method didn't seem to be needed any longer so they never replaced. I don't know if the word was released to developers and integrators that the "encryption algorithm" wasn't ideal for storage of sensitive information, but I don't know how many plugins or customizations use it either.

EXCEPT.... Microsoft still uses it for their GP system password, which is the password needed to get to the Security Roles/Tasks and all the User Security related forms while in GP. What's even worse, if you create a new user, you have to give the user explicit rights to the company or companies you want the user to access, but you DON'T HAVE TO GIVE ACCESS TO THE DYNAMICS DATABASE. What that means is if you create a base user in GP, that user can log into the SQL server and run a select statement on the table containing the "encrypted" GP System password... Not good...

I'm a Microsoft MVP for Dynamics GP and this line "What that means is if you create a base user in GP, that user can log into the SQL server and run a select statement on the table containing the "encrypted" GP System password... " is completely false. GP users can't log in to SQL using their GP passwords. The article doesn't state a version being used. On some older versions it was possible to chose to allow a user to access SQL with their GP login. This is not possible on any of the supported versions of Dynamics GP.
Additionally, the System password referred to has always been a second line of defense. Security has to be given to a particular window in the application before GP even asks for the System password. Relying on the System password alone for security has never been a best practice.
There are a number of other areas where the writer confuses different types of passwords and security in Dynamics GP making it clear that he's never actually used the application to understand how differnt passwords and settings interact to provide security.
Mark

On one hand I would like to believe you since my company will be rolling out a Dynamics deployment at some point in the future; on the other hand, you guys used a substitution cipher and called it "encryption". The fact that you're an MVP and you say some stuff is kind of meaningless in the face of such a gigantic failure.

"One major drawback to switching authentication modes is audit trails. AX and SL have made the move from SQL auth to Windows Auth. In doing so, they destroyed the audit trail at the database level. All DB updates are made by one user making it a massive challenge to determine who made a change to financial data. Many of the AX and SL companies we work with get dinged for this in each audit."

That's when PA-DSS takes affect. And PA-DSS applies to any application that stores or transmits cardholder data (credit card number). They require all that information to be stored using "strong encryption", which is defined as either TripleDES with a 168bit Key or AES. Bunch of other rules too for anything web-based. Like for one the database storing the data cannot be connected to the internet. Requires at least 2 servers with your web facing server having 2 nics. One that connects to a DMZ or has a

Anybody that's ever administered GP will tell you that its security is a complete and utter joke. It's basically non-existent, or "security through obscurity" at best.

All users are granted full access to the data in SQL Server, and security restrictions are implemented entirely in the front-end application. There's no secure application tier whatsoever - just a client application connecting to a database that's being treated as a dumb shared persistence layer. I've used MS Access to create more secure appli

This product; "Microsoft Dynamics GP" gets a lot of publicity - and since it's mostly unknown to the majority this must mean that the flaw in reality is unimportant and what will happen is that the bug gets corrected and the application gets a lot of free marketing.

You are more correct than you expected. The encoding algorithm is not a Caesar Cipher algorithm. Going by the code table in the article, Microsoft simply XORs the incoming data with 0xEE. To undo the cipher, XOR again with 0xEE.

Using XOR makes for really easy coding. Instead of having an encryption and decryption function, now only one function will do both.

Actually, XOR is frequently used for encryption, and very strong ciphers can be built by XORing the plaintext with carefully chosen bits. These are known as "stream ciphers," and the idea is to use a random number generator; the secret key is the seed you give the generator. As you note, the encryption and decryption functions are the same, which is one of the advantages (another, more important advantage is that you can create provably secure stream ciphers based on standard assumptions, such as the diff